I already came up with a workaround, but forgot to report back. In H9 Control, use the “Connect MIDI Device to Eventide Stompbox” to choose Helix as the MIDI source. Unfrtunately, this only works for one H9 at a time. If I connect two H9’s via USB and use the above setting, any MIDI commands sent by Helix are ignored by both H9’s.
So for now, I use Bluetooth for one H9 and USB for the other. If I want to add a third H9, I won’t be able to use MIDI whilst connected with H9 Control.
